Drupal is now importing interface translations. This can take a few minutes.
When it's finished, you'll get a confirmation page:The language <em>yourlanguage</em> has been created and can now be usedwith a summary of all translation files that have been pulled.

On the page: admin/config/regional/language
Select your new language as default

Manually updating the interface translations

Cron will now check for updated translations, and will report the update status on the status page: admin/reports/status

To execute updates, go to: admin/config/regional/translate

You should see English and your new language.

Choose the "Update" tab

You see a list of all modules and their translation status

On the bottom of the page, you can initiate an update

Updating the interface translation with drush

You can also use drush to update your translations:drush l10n-update Update translations.drush l10n-update-refresh Refresh available information.drush l10n-update-status Show translation status of available projects.